1. Field of the Invention
This invention relates to magnetic tape drives, and more particularly, to a receptacle for a tape cartridge.
2. Description of the Prior Art
In recent years, computer technology has greatly expanded the market for computers, including reasonably inexpensive small computers such as personal computers and computers for small businesses. The so-called floppy disk drives provide a common means of data storage for small computers. One floppy disk drive in common use today is the industry standard 51/4 inch minifloppy disk drive. One or more of these disk drives are typically mounted inside the computer console. A diskette is inserted or removed through one or more slots at the front of the console. In other applications, the minifloppy disk drive can be contained in a separate housing for use externally to the computer console. In either instance, it has become an industry practice to provide a 51/4 inch minifloppy disk drive as a package with standard exterior dimensions.
Floppy disk drives have proved to be convenient for many applications such as program loading and data interchange, but they have a limited data storage capacity. Because of this problem, larger capacity disk drives such as the so-called Winchester disk drives have been used in lieu of floppy disk drives in applications requiring greater data storage capacities. The Winchester-type disk drive generally comprises one, two or three hard disks on which data are recorded. A Winchester-type disk drive can provide a much higher data storage capacity and faster data access and data transfer times than a floppy disk drive. Accordingly, a common practice in small business applications is to use a combination of the minifloppy disk and the Winchester disk. In this way, the day's transactions can be recorded on one or two floppy disks and a full copy of the business's transactions can be made on a hard disk at weekly intervals or longer.
Recently, Winchester-type disk drives have been manufactured in a package with the same exterior dimensions and mounting hole locations as a standard 51/4 inch minifloppy disk drive. In this way, the Winchester disk drive can be conveniently installed in the computer console in place of a minifloppy disk drive to provide the larger data storage capacity.
Data storage for computer applications also can be provided by a magnetic tape drive instead of disk drives. In recent years, 1/4-inch cartridge tape drives have been replacing floppy disk drives in many applications because the tape cartridges are more compact, can store from about 15 to 50 times more data than diskettes, and have a lower cost per megabyte. The 1/4-inch tape cartridges also have a greater data storage capacity than comparable Winchester-type disk drives.
Tape cartridges such as the Scotch DC 300XL data cartridge made by 3M Co. are commonly used for data storage in cartridge drives. Briefly, this type of standard tape cartridge includes a 1/4-inch magnetic tape enclosed within a case. The tape is driven, in part, by an internal capstan, a portion of which is exposed at an edge of the cartridge case. When the cartridge is inserted into a receptacle in the tape drive unit, the exposed capstan engages a capstan driven by the tape drive motor for driving the tape. The tape cartridge also includes a door near a corner of the case. The door is normally spring-biased to a closed position for protecting the tape during storage and transport. When the cartridge is inserted in the tape drive unit, the door is tripped open to expose a portion of the tape for engaging the magnetic read/write head on the tape drive unit. The mechanism for guiding the cartridge into the receptacle not only trips the door open, but it also prevents the door from contacting the head when the cartridge is inserted or removed.
The magnetic tape cartridges used in magnetic tape drives are manufactured according to industry standards approved by the American National Standards Institute (ANSI). Magnetic tape drives, including the larger 1/2-inch tape drives, have been able to replace the industry standard larger disk drives, such as the 8-inch, 101/2 inch and 14-inch disk drives. However, the standard 1/4-inch tape drive units have not been able to replace either the 51/4 inch minifloppy disk drive or Winchester-type disk drive because the standard size 1/4-inch tape cartridge has been too large to fit into a tape drive unit that meets the standard exterior dimensions of the 51/4 inch disk drives. For instance, the standard exterior width of a 51/4 inch disk drive package is 5.75 inches. With the standard size tape cartridge inserted in a standard tape drive and the door on the cartridge held open to expose the tape, the cartridge case and the door in its open position cover a distance of 5.765 inches, i.e., a distance greater than the standard 5.75-inch width of the smaller disk drives.
The present invention provides a tape cartridge receptacle that allows a tape cartridge to be inserted into a tape drive package having the same standard exterior dimensions as the 51/4 inch disk drives.